From Alternative To Mainstream: '90s Comedians CONTINUES...

The Upright Citizens Brigade: 16. Amy Poehler, 17. Matt Besser, 18. Ian Roberts, 19. Matt WalshAfter splintering off from Chicago’s Second City and ImprovOlympic, the Upright Citizens Brigade moved to New York City to become one of the more celebrated improv/sketch groups of the 1990s, culminating in an eponymous cutting-edge sketch show airing on Comedy Central from 1998 to 2000. Also during the '90s, the UCB regularly performed sketches and comedy bits on Late Night with Conan O'Brien. Most importantly, however, the UCB acquired a small performance space in Chelsea and began teaching classes in 1999. Thirteen years later, the UCB Theatre has become of the most important institutions in comedy, expanding to three theaters (including one in LA), and its classes in improv and sketch have been a breeding ground for countless comedy talents of the past decade.

Amy Poehler has become the most recognizable cast member of the Upright Citizens Brigade, spending nearly a decade on Saturday Night Live, including over four seasons as host of "Weekend Update." She left to have a baby and star in her own series, Parks and Recreation, now in its fifth season and widely regarded to be one the best sitcoms of its generation.

Matt Besser, who founded the Upright Citizens Brigade while in Chicago, has been one of the most influential forces in expanding the UCB’s influence. He also created the TV news spoof show Crossballs on Comedy Central, and recently produced the movie Freak Dance, based on his long-running show at UCB.

Ian Roberts has established himself as a reliable comedy character actor, with memorable roles in Anchorman, Bring It On, and Talladega Nights, as well as a recurring role as a dimwitted doctor on Arrested Development. Roberts is currently a writer and executive producer on Comedy Central's Key & Peele.

Matt Walsh was one of the first correspondents on Jon Stewart’s version of The Daily Show (along with Steve Carell and Stephen Colbert). He was also a notable character actor in The Hangover and Junebug. After appearing in a handful of short-lived sitcoms, Walsh currently stars on the critically applauded, Emmy-winning HBO series Veep.

20. David Wain David Wain was rarely in front of the camera in his State days, with his most notable role being a recurring character in “The Jew, the Italian, and the Redhead Gay.” His knack for directing proved to be an asset, as he has directed several of the most notable comedies of the past decade, including the cult classic Wet Hot American Summer, The Ten, Role Models, and Wanderlust. His most famous recent credit, however, may be as a creative force behind Children’s Hospital, a watershed show for Cartoon Network’s Adult Swim. Wain was also a member of Stella with fellow State vets Michael Ian Black and Michael Showalter. And he has starred in his own long-running web series Wainy Days since 2007.